Abstract
S-Methyl thioacetate (MeSAc) production by brewer's yeast from methyl mercaptan (MeSH) was investigated under various conditions. At optimum, 98 mg/liter of MeSAc was produced from 500 mg/liter of MeSH contained in culture broth. The MeSAc level in yeast growth mediumwas increased with increasing MeSH at relatively low levels (10 to 500 mg/liter). However, higher MeSH levels in medium (over 1 g/liter) inhibited yeast growth, and no MeSAc was produced. MeSAc was formed readily by incubating MeSH with yeast resting cells. Furthermore, S-ethyl or S-n-propyl thioacetate accumulated in yeast cell suspension when ethyl or n-propyl mercaptan, respectively, was incubated with resting cells. MeSAc was also produced from L-methionine by brewer's yeast, but its formation was dramatically inhibited by copper ions. This finding suggests that MeSHis an intermediate product between L-methionine and MeSAc.
